package com.heima.schedule.service.impl;

import com.alibaba.fastjson.JSON;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.heima.common.constants.ScheduleConstants;
import com.heima.common.redis.CacheService;
import com.heima.model.schedule.dtos.Task;
import com.heima.model.schedule.pojos.Taskinfo;
import com.heima.model.schedule.pojos.TaskinfoLogs;
import com.heima.schedule.mapper.TaskinfoLogsMapper;
import com.heima.schedule.mapper.TaskinfoMapper;
import com.heima.schedule.service.TaskService;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Set;

@Service
@Slf4j
@Transactional
public class TaskServiceImpl implements TaskService {

    @Autowired
    private TaskinfoMapper taskinfoMapper;

    @Autowired
    private TaskinfoLogsMapper taskinfoLogsMapper;

    @Autowired
    private CacheService cacheService;

    @Override
    public long addTask(Task task) {

        //1.添加任务到数据库中
        boolean success = false;
        success = addTaskToDb(task);

        if (success) {
            //2.添加任务到redis中
            addTaskToCache(task);
        }

        return task.getTaskId();
    }

    /**
     * 取消任务
     * @param taskId
     * @return
     */
    @Override
    public boolean cancelTask(long taskId) {
        boolean flag = false;

        //删除任务，更新日志
        Task task = updateDb(taskId,ScheduleConstants.CANCELLED);
        
        //删除redis数据
        if (task != null) {
            removeTaskFromCache(task);
            flag = true;
        }
        
        return flag;
    }

    @Override
    public Task poll(int type, int priority) {
        Task task = null;
        try {
            String key = type + "_" + priority;
            String task_json = cacheService.lRightPop(ScheduleConstants.TOPIC + key);
            if (StringUtils.isNotBlank(task_json)) {
                task = JSON.parseObject(task_json, Task.class);
                //更新数据库信息
                updateDb(task.getTaskId(),ScheduleConstants.EXECUTED);
            }
        } catch (Exception e) {
            e.printStackTrace();
            log.error("poll task exeption");
        }
        return task;
    }

    /**
     * 未来数据定时刷新
     */
    @Override
    @Scheduled(cron = "0 */1 * * * ?")       //定时任务-每分钟
    public void refresh() {
        //System.out.println(System.currentTimeMillis() / 1000 + "执行了定时任务");
        String token = cacheService.tryLock("FUTURE_TASK_SYNC", 1000 * 30);
        if (StringUtils.isNotEmpty(token)) {
            log.info("未来数据定时刷新---定时任务");
            //获取所有未来数据集合的key值
            Set<String> futureKeys = cacheService.scan(ScheduleConstants.FUTURE + "*"); // future_*

            for (String futureKey : futureKeys){  // future_250_250
                //获取当前数据的 key topic
                String topicKey = ScheduleConstants.TOPIC + futureKey.split(ScheduleConstants.FUTURE)[1];
                //按照key和分组查询符合条件的数据
                Set<String> tasks = cacheService.zRangeByScore(futureKey, 0, System.currentTimeMillis());
                //同步数据
                if(!tasks.isEmpty()) {
                    //将这些任务添加到消费者队列中
                    cacheService.refreshWithPipeline(futureKey,topicKey,tasks);
                    System.out.println("成功将" + futureKey + "下的当前需要执行的任务数据刷新到" + topicKey + "下");
                }

            }
        }
    }

    @Scheduled(cron = "0 */5 * * * ?")
    @PostConstruct
    public void reloadData() {
        clearCache();  //情况缓存中数据，避免新增到缓存中的数据重复
        log.info("数据库数据同步到缓存");
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MINUTE,5);

        //查看小于未来5分钟的所有任务
        LambdaQueryWrapper<Taskinfo> wrapper = Wrappers.<Taskinfo>lambdaQuery().lt(Taskinfo::getExecuteTime, calendar.getTime());
        List<Taskinfo> allTasks = taskinfoMapper.selectList(wrapper);
        if (allTasks != null && !allTasks.isEmpty()){
            for (Taskinfo taskinfo : allTasks) {
                Task task = new Task();
                BeanUtils.copyProperties(taskinfo,task);
                task.setExecuteTime(taskinfo.getExecuteTime().getTime());
                addTaskToCache(task);
            }
        }

    }

    private void clearCache() {
        //删除缓存中未来数据集合和当前消费者队列的所有key
        Set<String> futureTasks = cacheService.scan(ScheduleConstants.FUTURE + "*");
        Set<String> topicTasks = cacheService.scan(ScheduleConstants.TOPIC + "*");
        cacheService.delete(futureTasks);
        cacheService.delete(topicTasks);
    }

    /**
     * 删除redis中的任务数据
     * @param task
     */
    private void removeTaskFromCache(Task task) {
        String key = task.getTaskType() + "_" + task.getPriority();
        if (task.getExecuteTime() <=System.currentTimeMillis()) {
            cacheService.lRemove(ScheduleConstants.TOPIC + key,0,JSON.toJSONString(task));
        } else {
            cacheService.zRemove(ScheduleConstants.FUTURE + key,JSON.toJSONString(task));
        }
    }

    /**
     * 删除任务，更新任务日志状态
     * @param taskId
     * @param status
     * @return
     */
    private Task updateDb(long taskId, int status) {
        Task task = null;
        try {
            //删除任务
            taskinfoMapper.deleteById(taskId);

            TaskinfoLogs taskinfoLogs = taskinfoLogsMapper.selectById(taskId);
            taskinfoLogs.setStatus(status);
            taskinfoLogsMapper.updateById(taskinfoLogs);

            task = new Task();
            BeanUtils.copyProperties(taskinfoLogs,task);
            task.setExecuteTime(taskinfoLogs.getExecuteTime().getTime());
        } catch (BeansException e) {
            log.error("task cancel exception taskid={}",taskId);
        }
        return task;
    }






    /**
     * 添加任务到redis中
     * @param task
     */
    private void addTaskToCache(Task task) {

        String key = task.getTaskType() + "_" + task.getPriority();

        //获取5分钟之后的时间  毫秒值
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MINUTE,5);
        long nextScheduleTime = calendar.getTimeInMillis();

        //2.1 若任务执行时间小于等于当前时间，存入list
        if (task.getExecuteTime() <= System.currentTimeMillis()) {
            cacheService.lLeftPush(ScheduleConstants.TOPIC + key, JSON.toJSONString(task));
        } else if (task.getExecuteTime() <= nextScheduleTime) {
            //2.2 若任务执行时间大于当前时间 && 小于等于预设时间（未来5分钟）存入zset
            cacheService.zAdd(ScheduleConstants.FUTURE + key, JSON.toJSONString(task),task.getExecuteTime());

        }

    }


    private boolean addTaskToDb(Task task) {
        boolean flag = false;

        //保存任务表
        try {
            Taskinfo taskinfo = new Taskinfo();
            BeanUtils.copyProperties(task,taskinfo);
            taskinfo.setExecuteTime(new Date(task.getExecuteTime()));
            taskinfoMapper.insert(taskinfo);

            //设置taskId
            task.setTaskId(taskinfo.getTaskId());

            //保存任务日志数据
            TaskinfoLogs taskinfoLogs = new TaskinfoLogs();
            BeanUtils.copyProperties(taskinfo,taskinfoLogs);
            taskinfoLogs.setVersion(1);  //乐观锁版本号
            taskinfoLogs.setStatus(ScheduleConstants.SCHEDULED);  //初始化状态
            taskinfoLogsMapper.insert(taskinfoLogs);
            flag = true;
        } catch (BeansException e) {
            throw new RuntimeException(e);
        }
        return flag;
    }
}






















